Didn't see it myself but I'm curious - did you notice any sound at all? The triangular ones seem to split opinion on whether they make that low hum or nothing at all.
I'm based in Glastonbury so Lake Michigan is a bit out of my patch, but I've been following these sightings for years and the triangular formation keeps coming up across both sides of the Atlantic. There was a cluster of similar reports around the Somerset Levels back in 2019 that I got quite deep into.
What direction was it moving, and roughly how long did it stay visible before it went? Those two details tend to be the most useful when you're trying to work out whether its something conventional or genuinely worth logging properly.